Childbearing, marriage and human capital investment

This paper proposes and tests a simple joint explanation for i) increases in marital and nonmarital birth rates in the United States over recent decades, ii) the dramatic rise in the share of nonmarital births, and iii) the pronounced racial differences in the timing of childbearing. The explanation arises from differences across time and race in the attractiveness of marriage and opportunities for investment in human capital. For given preferences, a decline in the marriage rate necessarily causes both the marital and nonmarital birth rates to increase, with no change in the total birth rate. This model exhibits exceptional power in replicating salient features of childbearing behavior. Our results suggest that changes in marital and nonmarital birth rates, as well as in the share of nonmarital births, arose primarily from changes in marriage behavior, not from changes in fertility; and that racial differences in the timing of childbearing reflect early differences in human capital investment.